Field of the Disclosure
Embodiments of the present invention relate to a liquid crystal display device, and more particularly, to a liquid crystal display device using a conductive tape which facilitates to repair a backlight unit and internal parts.
Discussion of the Related Art
A liquid crystal display device displays an image by applying a voltage so as to change an alignment of liquid crystal molecules. Optical properties such as birefringence, optical activity, dichromatic and light-scattering properties are changed into visual properties in a liquid crystal cell which passes light upon the alignment of the liquid crystal molecules. That is, the liquid crystal display device displays information through the use of light modulation by the liquid crystal cell. The liquid crystal display device may include a backlight unit provided below a liquid crystal display panel. An image is displayed by the use of light emitted from the backlight unit.
Typical driving modes, that is, the most-generally used driving modes of the liquid crystal display device are a Twisted Nematic (TN) mode and an In-Plane Switching (IPS) mode. In the TN mode, a liquid crystal director (vector component) is aligned while being twisted by 90°, and a voltage is applied thereto, thereby controlling the liquid crystal director. In the IPS mode, two electrodes are provided on one substrate, whereby a liquid crystal director is twisted on a plane being in parallel to an alignment film.
In case of the IPS mode, pixel electrodes and common electrodes are formed in a pixel region of a lower substrate, whereby an in-plane electric field (i.e., horizontal electric field) is produced between the pixel and common electrodes, and a liquid crystal layer is aligned by the in-plane electric field.
FIG. 1 is a cross sectional view illustrating a related art liquid crystal display device. FIG. 2 illustrates a problem occurring when a backlight unit is separated from the related art liquid crystal display device shown in FIG. 1.
Referring to FIG. 1, the related art liquid crystal display device may include a cover glass 10, a liquid crystal display panel 20, a resin layer 30, a backlight unit 40, and a conductive tape 50.
The cover glass 10 protects the liquid crystal display panel 20. The cover glass 10 is attached to a front surface of the liquid crystal display panel 20, wherein the resin layer 30 is interposed between the cover glass 10 and the liquid crystal display panel 20.
The liquid crystal display panel 20 may include first and second substrates 21 and 22 bonded to each other with a liquid crystal layer interposed therebetween, a lower polarizing film 23 attached to a rear surface of the first substrate 21, an antistatic layer (electrostatic prevention layer) 24 provided on an upper surface of the second substrate 22, and an upper polarizing film 25 attached to the antistatic layer 24.
The resin layer 30 is coated onto a rear surface of the cover glass 10, to thereby bond the cover glass 10 and the liquid crystal display panel 20 to each other. In this case, the resin layer 30 is attached to an upper surface of the conductive tape 50 as well as the upper polarizing film 25 of the liquid crystal display panel 20.
The backlight unit 40 is disposed at a rear side of the liquid crystal display panel 20 so that a uniform flat light is emitted from a light source toward the liquid crystal display panel 20. According to a location of the light source with respect to a display surface, the backlight unit 40 may be classified into an edge type and a direct type.
The conductive tape 50 is attached to an upper edge of the antistatic layer 24 formed on the second substrate 22, and is also attached to a rear surface of the backlight unit 40 along lateral surfaces of the liquid crystal display panel 20 and the backlight unit 40.
In order to prevent static electricity produced in the second substrate 22, the conductive tape 50 electrically connects the antistatic layer 24 formed on the second substrate 22 and the rear surface of the backlight unit 40, thereby grounding any static electricity. To this end, the conductive tape 50 may be formed in a structure of sequentially stacking a conductive adhesive layer, an aluminum (Al) conductive layer, and a polyethylene (PET) resin layer.
Hereinafter, a problem of the related art liquid crystal display device will be described with reference to FIG. 2.
For disassembling and repairing the backlight unit 40 and corresponding internal parts, it is necessary to strip off or remove the conductive tape 50 from the backlight unit 50. However, when the conductive tape 50 is first stripped off, the conductive tape 50 may be wrinkled. Thus, it is impossible to reuse the conductive tape 50, and also to replace the conductive tape 50. For replacement of the conductive tape 50 attached to the resin layer 30, the cover glass 10 and the liquid crystal display panel 20 bonded to each other by the resin layer 30 should be separated from each other. During this process, cracks and defects to the liquid crystal display panel 20 may be caused. In this case, if it is difficult to repair the liquid crystal display panel 20, a production yield rate may be lowered, and the liquid crystal display device may be wasted. That is, when trying to repair the backlight unit 40 and/or any internal parts, a complicated disassembling process of the corresponding parts including difficulties in separating the cover glass 10 from the liquid crystal display panel 20 bonded thereto via the resin layer 30 can cause cracks and defects, which lead to problems in repairing the liquid crystal display device.
The above background description for the related art liquid crystal display device is based upon knowledge or information previously known or newly obtained as a result of research by the present inventors leading to the concepts and embodiments of the present invention. That is, such related art description is not prior art that was well-known to the general public before the conception and/or application date related to the technical matter disclosed hereafter.